Table 1.
Baseline characteristics of overall participants and groups stratified by admission serum calcium levels
| Variables | Overall | Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 | P-value |
|---|---|---|---|---|---|---|
| Serum calcium (mmol/L) | <2.12 | 2.12 to <2.21 | 2.21 to <2.28 | ≥2.28 | ||
| Number of patients | 3,109 | 702 | 848 | 712 | 847 | |
| Age (years) | 64.41 ± 10.75 | 66.11 ± 10.28 | 64.92 ± 10.52 | 63.85 ± 10.80 | 62.97 ± 11.61 | <0.001 |
| Male, n (%) | 2,469 (79.4) | 576 (82.1) | 696 (82.1) | 549 (77.1) | 648 (76.5) | 0.004 |
| Previous or current smokers, n (%) | 1,855 (59.7) | 434 (61.8) | 520 (61.3) | 420 (59.0) | 481(56.8) | 0.146 |
| Hypertension, n (%) | 1,717 (55.2) | 375 (53.4) | 439 (51.8) | 406 (57.0) | 497 (58.7) | 0.018 |
| Diabetes, n (%) | 754 (24.3) | 175 (24.9) | 187 (22.1) | 167 (23.5) | 225 (26.6) | 0.163 |
| Previous PCI or CABG, n (%) | ||||||
| PCI | 362 (11.6) | 77 (11.0) | 104 (12.3) | 96 (13.5) | 85 (10.0) | 0.165 |
| CABG | 35 (1.1) | 6 (0.9) | 9 (1.1) | 7 (1.0) | 13 (1.5) | 0.594 |
| Previous drug treatment, n (%) | ||||||
| Aspirin | 1,156 (37.2) | 211 (30.1) | 321 (37.9) | 290 (40.7) | 334 (39.4) | <0.001 |
| Statin | 770 (24.8) | 140 (19.9) | 201 (23.7) | 214 (30.1) | 215 (25.4) | <0.001 |
| ACEI or ARBs | 652 (21.0) | 124 (17.7) | 182 (21.5) | 149 (20.9) | 197 (23.3) | 0.059 |
| Beta-blocker | 817 (26.3) | 136 (19.4) | 225 (26.5) | 207 (29.1) | 249 (29.4) | <0.001 |
| BMIa | 24.16 ± 2.92 | 24.01 ± 2.82 | 23.95 ± 2.83 | 24.27 ± 2.84 | 24.39 ± 3.12 | 0.006 |
| Blood pressure at admission (mmHg) | ||||||
| Systolic | 130.35 ± 21.29 | 126.67 ± 23.33 | 129.38 ± 19.55 | 132.71 ± 21.17 | 132.40 ± 20.86 | <0.001 |
| Diastolic | 76.58 ± 12.58 | 74.42 ± 13.34 | 75.76 ± 11.97 | 77.41 ± 12.72 | 78.49 ± 12.09 | <0.001 |
| Heart rate at admission (beats/min) | 74.06 ± 13.86 | 75.58 ± 15.93 | 73.52 ± 13.38 | 73.17 ± 12.35 | 74.09 ± 13.63 | 0.006 |
| Creatinine clearanceb | 70.28 ± 29.29 | 68.85 ± 24.82 | 69.94 ± 25.12 | 71.44 ± 40.68 | 70.82 ± 24.81 | 0.367 |
| Total cholesterol (mmol/L) | 4.09 ± 1.10 | 3.79 ± 0.96 | 4.02 ± 1.11 | 4.22 ± 1.11 | 4.28 ± 1.14 | <0.001 |
| LDL-cholesterol (mmol/L) | 2.39 ± 0.94 | 2.24 ± 0.80 | 2.33 ± 0.95 | 2.45 ± 0.90 | 2.53 ± 1.03 | <0.001 |
| Triglyceride (mmol/L) | 1.75 ± 1.13 | 1.47 ± 0.80 | 1.70 ± 1.19 | 1.79 ± 1.18 | 1.98 ± 1.20 | <0.001 |
| HDL-cholesterol (mmol/L) | 1.15 ± 0.35 | 1.12 ± 0.42 | 1.13 ± 0.35 | 1.18 ± 0.34 | 1.17 ± 0.30 | 0.002 |
| Serum potassium (mmol/L) | 3.96 ± 0.45 | 3.85 ± 0.52 | 3.95 ± 0.42 | 3.99 ± 0.42 | 4.02 ± 0.44 | <0.001 |
| Serum sodium (mmol/L) | 141.00 ± 3.63 | 140.20 ± 4.47 | 141.08 ± 3.22 | 141.38 ± 3.46 | 141.27 ± 3.28 | <0.001 |
| Serum chloride (mmol/L) | 102.7 ± 18.15 | 105.47 ± 5.72 | 105.35 ± 3.28 | 104.67 ± 5.28 | 104.12 ± 5.78 | <0.001 |
| Lesion characteristic, n (%) | ||||||
| Left main disease, n (%) | 290 (9.3) | 72 (10.3) | 78 (9.2) | 62 (8.7) | 78 (9.2) | 0.784 |
| Triple vessel disease, n (%) | 661 (21.3) | 145 (20.7) | 170 (20.0) | 166 (23.3) | 180 (21.3) | 0.441 |
| ACS, n (%) | 2,229 (71.7) | 534 (76.1) | 601 (70.9) | 491 (69.0) | 603 (71.2) | 0.22 |
| PCI, n (%) | 2,207 (71.0) | 511 (72.8) | 599 (70.6) | 490 (68.8) | 607 (71.7) | 0.396 |
| Drug treatment in hospital and during follow-up, n (%) | ||||||
| Aspirin | 2,954 (95.0) | 665 (94.7) | 808 (95.3) | 677 (95.1) | 804 (94.9) | 0.965 |
| Clopidogrel | 2,866 (92.2) | 624 (92.2) | 779 (91.9) | 657 (92.3) | 783 (92.4) | 0.976 |
| Statin | 2,890 (92.2) | 655 (93.4) | 786 (92.7) | 667 (93.7) | 782 (92.3) | 0.699 |
| ACEI or ARBs | 1,843 (59.3) | 385 (54.8) | 491 (58.0) | 435 (61.1) | 532 (62.8) | 0.009 |
| Beta-blocker | 2,123 (68.3) | 429 (61.1) | 559 (66.0) | 506 (71.1) | 629 (74.3) | <0.001 |
| Nitrated derivative | 1,399 (45.0) | 281 (40.0) | 394 (46.5) | 329 (46.2) | 395 (46.6) | 0.028 |
Data are expressed as mean ± SD or counts and percentages, as appropriate. ACEI: angiotensin-converting enzyme inhibitors, ACS: acute coronary syndrome, ARBs: angiotensin-receptor blockers, CABG: coronary-artery bypass grafting, PCI: percutaneous coronary intervention.
aBody mass index is the weight in kilograms divided by the square of the height in meters.
bCreatinine clearance was calculated using the Cockcroft–Gault equation (mL/min).